Printing-telegraph.



A. (L GREHURE.

PRINTING TELEGRAPH.

APPLICATION FILED .TAN.16,1905.

Patented Apr. 6, 1909.

Z SHEETS-SHEET 1.

A. C. OREHORE.

PRINTING TELEGRAPH.

APPLICATION FILED JAN.16,1905.

IWZMO 1 WiZ'nes as: y .fizven 'or:

WW Aiz Patented Apr. 6, 119%.

I printing sr'r ALBERT C. CREHORE, OF YONKERS, NEW YORK, ASSIGNOR TOTYPEWRIIING TELEGRAPH l COMPANY, OF NEW YORK, N. Y., A CORPORATION OFNEW YORK.

PRINTING-TELEGRAPH.

Specification of Letters Patent.

Patented A rire, ieoe.

Application filed January 16, 1905. Serial No. 2 .4259.

To all whom it may concern:

Be it known that I, ALBERT C. CREHORE, a citizen of the United States,residing at Yonkers, county of WVestchester, Stateof New York, haveinvented certain new and useful Improvements in Printing-Telegraphs, ofwhich the following specification and accompanying drawings illustrateone form of the invention which I now regard as the best .out of thevarious forms in which the inven ada )ted too crate the res ective he sof a l P H Y typewriter, are individua y selected and operated by therespective keys of a typewriter key-board at the sending station. Inthat system I provided,- at the receiving station, two groups of linerelays, one group in each of the two line wires, and, by thesimultaneous action of the two line wires, I selected and operated apair of those relays, one from each group, which, in turn, served, bymeans of two secondary relays, to work two circuit closers placed inseries in the local circuit of some one of-the series of or receivingmagnets. In my present invention I have a similar arrange ment, exceptthat I employ but one line wire and, by means thereof, select and oerate the two desired line relays successive y instead ofsimultaneously. I also-employ but six main line'relays instead oftwelve,since I make the selection of the two relays by two impulses over thesame line wire for each letter, and, whereas in the former case the twoimpulses (on the two separate line wires) acte respectively on thetwo'groups of line relays, in the present casethe first ,im ulse' mayact u on the six relays as be 'ore, and the secon impulse may act againon the same relays just as if they were a different group. .In one sensetherefore I still have two groups of relays, the same relays'i'servingfirst in {the character of oneofv my former grou s, and next in thecharacter of the other. 0 m former groups. tically, however, 1 ain theadvantage of requiring but six reIays instead of twelve. In order thatthese six relays may act first in one character in response to the firstimpulse, and then in another character in re s onse to the secondimpulse, I rovide a s nrnr onto. j

.55 Pracevice which I designate as a trans er switch, I

that acts to give the line relays control of one or the other of twosets of secondary relays, each set containing six magnets, and two ofthem, one from each set, controlling the two circuit closers laced inseries in the circuit of some one o the 36 printing magnets. I

also provide means for automatically operating the transfer switch, sothat for the first main line impulse it will act upon one set ofsecondary relays, and the second impulse upon the other set.

Certain other features of novelty will appear as this descri tion iscontinued.

Turning to the rawings as an illustration of the system to be described,I will first consider the arrangements at the transmitting station, itbeing remembered that I must provide therein for the sending, for eachcharacter or letter to be selected andprinted,

of two successive impulses over a single main line. In other res ectsthe transmitting apparatus is substantially like that of my'l'ormerappllication, there 'bein a series of magnetica y operated contactevers, which serve to send currents of six difierent kindsdiflerentiated by polarity and also by strength. I provide, as before,three difierent values of current, each of which may be of one polarityor the other, making (idifierent kinds of current in all.

Referring to Fig. 1, the transmitting ap paratus is shown mup .er part,and the receiving apparatus in t e lower Iitit of the figure, the twobeing connected their back stopsibyasprings. Two sources I of current,.conventionally represented as batteries, are; provided, indicatedrespecy the line. wire L. The line wire, entering the trans-f its frontstop, it will simultaneously 'to the sections of battery tively as S andS one serving-to send positive and the other negative currents to theline L; Both batteries have one of their two terminals connected toground permane'ntly, this being an advantageous arrangement for severalreasons. The opposite terminals of the twobatteries are connectedrespectively to the front stops it and 7c of the several contact'l'eversaforesaid; while the front stops of the remaining levers are connectedto intermediate points in the respective batteries, so as to receivetherefrom an electromotive force smaller than that produced by theentire battery. Thus contact k is connected to the first batterysection, and k to the secondary battery section, so as to receiverespectively one-third and two-1v 'of the one operated. By this means Iam enabled to transmit to the line L any one of the six different kindsof current heretofore mentioned, while between the current impulses theline L will be grounded and dis charged. This grounding of the linebetween the successive current impulses is a feature of practicalimportance in the operation of m system, which also employs current of aow frequency, by reason of which it may be used to. advantage ontelephone circuits without interfering with the simultaneoustransmission of the telephone current.

' For operating the respective contact levers D .D I provide thecorresponding magnets (l -d, which all have one of their terminalsconnected to the local battery G by the wire 7, while their oppositeterminals are connected individually to the opposite termiseveral'transmitting keys.

each magnet twice, to sen nal of G by the contacts 13 16, or 1415 of theIt is manifest that in operating the six magnets in groups of two each,there are 36 possible combinations, including as one grou the operationof two current im pulses of the same kind over the line wire L insuccession. These 36' combinations are shown in the diagram, the firstimpulse being produced by closure of the contacts 13 16 andthe second bythe closure of the contacts 14 15, these closures beingseparated by anintervalduring which the line is grounded as aforesaid. For example, theterminal 1 of m et d;,is connected to thewires 36 and 30,; the latterbeing connected to the lower' six contacts 14 and the former-being con-'magnet 11 asecond time. On the other hand,

. tively the 36 at the point 17 and provided at one end with nected tosix ofthe contacts 13 distributed as shown in the'diagram. The contacts15 and 16 are connected by the wire X to the battery G. In a similar waythe terminal 2 of magnet d is connected tothe wires 37 and 31; theterminal 3 of magnet d? to the wires 38 and 32; the terminal 4 of magnetd to the wires 39 and 33; the terminal 5 of magnet d to the wires 40 and34, and the terminal 6 of magnet d to the wires 41 and 35, Then if wetake the upper one of the vertical series of contacts, it is manifestthat the closure of 13 16 will energize magnet d while the succeedingclosure of contacts 14 15 will operate the taking the contacts oppositethe letter X the closure of 13 16 will, through the line 38, energizemagnet (1 while the closure of 14 15 through the line 33 will energizemagnet d". In this manner the successive closure of the several sets ofcontacts will operate respeca-irs of magnets and thereby send for eachetter or character transmitted a pair of succeeding current im ulsesdiffer- 'entiated in character from al of the remaining 35 pairs.Turning to Figsy'3 and 4, I'have shown therein a-key for operating twosets of contacts in succession. The key lever is pivoted the button 20by which it may be depressed against a stop 19. The opposite end of thelever is normally held down by a spring 18 I I against a stop 24. Nearthe extremity of this end of the lever is a pin 16 oval in cross 100section projecting from one side of the lever, as shown in Fig. 3. Thispin is the contact 16 which I have already referred to. Its comradecontact 13 consists 'ofa spring 13 fastened to a block 25 and normallyresting 105 drop back and carry'the plate with it, so that 5 the returnor downward stroke of the pin 16 will pass over the insulated side ofthe plate 21 and produce no electrical connection between 16 and 13. Thesecondvset of contacts 14 and 15 are mounted on opposite sides 120 ofthe block 26, the former taking the form of a s ring attached at one endto the under side 0 the block 26, and at the other end to a .block 27 ontheu-pper edge of the key lever;

while the latter takes the form of a screw in 125 the end of a plate 28.The depression of the key lever by the button 20 wil first close thecontacts 13 16, as already described, then break the circuit, then closethe contacts 14-,

15, and then, on its-return stroke, will break 130 in- 16 rises, it willfirst come in 0 the connection between 14 and. 15 and the circuit willremain broken until the return stroke of the lever is complete.

.1 be a series of such key levers, 36 in number,

or as many of the 36 as one may desire to use;

and the whole will make up. a transnrfitting key board similar to thekey board of. an orthe receiving apparatus up to the point where thetransmission of the two impulses, in the manner just described, serves,at the receiving station, to select and operate some one pair of thesecondary relays WVV "lhe manner in whiclrthese two secondary relaysthen select and operate some individual-printing magnet is shown in Fig.2, being identical with the arrangement for this purpose provided in myformer arrangement. At the receiving station the main line L passesthrough six polarized relays in series (shown at the bottom of thefigure) and goes thence to ground or to another station on the sameline. The first of these six relays is designated R 6, 12, these twonumerals indicating'that during one of the two line impulses the relaywill control the secondary relay W and during the second impulse thesecondary relay W. The remaining relays are similarly designated by thenumerals of the secondary relays which they respectively control at eachone of the two impulses.

prefer to give these relays a permanent ad-' justment and then n aintainthe line currents which pass through them substantiallyfunchanged by ashunting resistance F. By this means the different current. strengths towhich the several relays res ond will be maintained unchanged. 'One alfof the six relays respond to positive currents only and the other halfto negative currents only. Assuming that the left-hand three respond topositive currents, the relay R 6, 12 will alone respond to the weakestpositive current. It and the next relay R 5, 11 will respond to themedium current, while all three will respond to the strongest current.The armatures of these relays are normally held against their backstops, and the local circuit from battery Pcomes by the wire 42 to thelever of relay R 4, 10 and goes thence by its backstop to the lever ofIt 5, 11 and thence by its back stop to the lever of R 6, 12 at whichthe circuit is normally broken. 7 There There will I'pre'fer, however,

- ondary relays.

R 6, 12 will alone respond and throw its To a mediunr I lever againstthe front stop 1. current the relay R 5, 11 will also respond, but willinstantly break at its back stop, the

local circuit-connection, leading to the lever 'ofR 6, 12, so that whilethe latter relay may operate, itwill' have no efiect upon the localcircuit. Similarly, relay R4 10 will respond' I to the strongest,current and immediately break, at its back sto thelocal circuit connections leading to t e levers of the other two relays which willoperate but have no efiect upon the local circuit. In this way,by-sending the pro er strength of positive current, any desire one ofthethree relays {ust mentioned may be operated and, simiarly, bysending. any one of the three available strengths of negative current,any desired one of the remaining three relays can be selected andoperated. The one of the six. relays thus selected will, on the first ofthe two' impulses required for the "trans-n mission of each letter,operate one of the lower sets of sixsecondary relays W' W and, on thesecond impulse -will operate some one of the upper set of six secondaryrelays Vv W '1 his difierentiation' between the relay action on thefirst and second impulses, is produced by means of a transfer switch M,which transfers the control ex- A.

ercised by the relays first t0 the lower set,

and then to the u per set of secondary relays.

The switch M 1s normally spring biased to the left, so as to conneet inmultiple with the six contacts'leading to the lower set of sec: Thecircuit of battery P passes through the switch-retaining magnet m of thetransfer switch M, from the lefthand contact plate of that switch, whichbears "upon the six contaets'aforesaid and thereby. connectsone terminalof each of the I lower set of secondary relays to they battery P inmultiple. The other terminals of these relays are connected individuallyand respectively to the front contacts 1 of the six line relays; 'while,as aforesaid, the levers of these relayscommunicate with the oppositeterminal of battery P. Thus, in the biased position of the switch M, theseveral relay contact leverswill close the local ireuits of the severalsecondary relays VV -W', while the relay thus operated will retain itsarmature by the closure of a locking coil-II at the contacts", thiscontact being additional to contact 0 by which, as will be hereinafterexplained, the relay acts oii-the printing magnets. For example, we mayassume that relay R 3, 9 closes the circuit of secondary relay VV Thenthe contact lever of W will clogethe local locking circuit as follows:batteiy P, wire 43, contact lever of W, locking 0011 H wire 4-4,releasing sw tch B, wire 51,

shifting magnet on to the opposite terminal of battery P. This locking;circuit will refore, when a weak current flows, the relay 1 main closeduntil the releasing switch B is opened. by the action of one of theprinting magnets J, it being understood that all the printing magnetswill, at the limit of their stroke, act upon the switch B to break thelocking circuit. At the same time the energizing of shifting magnet mwill have a tendency, which, however, is ineffective, to move thetransfer lever M. So long as the first one of the two current impulsesis going over the line wire L (operating, as we have assumed, the relayR 3, 9 which operates in turn the secondary relay VI) the retainingmagnet m aforesaid will remain energized and prevent the shifting of theswitch M. So soon, however, as the first impulse comes to an end, the

4 relay R 3, 9 will be denergized and will open the operating circuit ofW which includes also the retaining magnet m This will allow thetransfer switch M to move to the right, and connect battery P to theupper set of secondary relays WVV the circuit from the battery P passingthrough retaining H m of the transfer-switchon its way to the contactplate of switch M to the right of the switch, just as it passed throughthe retain-.

ing coil m on its way to the contact plate at the left of the switch. Itwill be remembered that, during this time, the locking circuit,

which retains the armature of secondary relays VV is still in action.After the switch M has been shifted'as aforesaid, one of the six linerelays will again be operated by the second line impulse, and will actto select and. operate one of the six secondary relays of the upper setW VV as they selected and operated one of the six secondary relays W-JV, the latter set being now open-circuited at switchM and the, formerset having their circuits closed at the same oint. Thus the current frombattery]? an line 42 will go to the armature lever of that one of thesix relays which has been selected and will pass thence to one of theupper set, instead of to one of the lower set, of secondary relays,since the circuit leading from each armaturelever is branched to twosecondary relays, one in the lower and the other in the upper set (forexam le the circuit from the armature-lever of 6, 12 branches to thelower secondary relay IN and the up er secondary relay W") and thecurrent will one of the two relays whose circuit is closed at the switchM. The one of the upper set as the transmitting key is hel pass to thatis permitted to rise at the sending station I 7 I have thus describedhow, for t e trans. mission of any desired letter. or character, a

key at the sending station will be depressed,

thereby sending two current impulses in Succession which have, in themanner described, selected and operated that pair of seconda relayswhich corresponds to the key that has been operated. In like manner eachone of the transmitting keys will select and operate some one air of the12 secondary relays W W t ere being 36 keys and 36 pairs of relaysavailable'from the 12 relays.

In Fig. 2 I represent a series of printing 'magnets which are dividedinto six groups,

those in each group havingtheir terminals on one side all connected inmultiple to the same wire. Thus there are six such wires 63, 64, 65, 66,67, 68 leadin respectively to circuit closers operated by t e severalsecondary relays W -W which, when closed, connect them to one terminalof the battery P. The opposite terminals of the magnets in each groupare connected respectively to circuitclosers operated by the severalsecondary relays N .W and, since there are six groups eachotthe saidrelays controls six ,circuit .closers one from a ma net in each of thesix groups. The circuit c osers all lead, by the wire 69, to-theopposite terminal of battery P. It is therefore evident that if twosecondary relays are energized, one from each of the two groups ofsecondary relays, they will the manner already explained. Then it willappear that W will connect wire 66 to battery P, and the wire will putall the terminals of the group of printing magnets to which it pertainsin connection with the battery. But of the opposite terminals of themagnets inthis group, only one of them, to wit, that of the magnet J,leads by wire 70 (Fig. 2) to the circuit closers of W. Hence that onemagnet will be energized, its circuit leading from battery 1?, by wire66and circuit closer of W 3 onthe one side, and on the other side fromthe opposite battery terminal, by the circuitcloser of V2 and wire 70.In like manner, any one of the 36 printing magnets may be selected andoperated by the action of two secondary relays, one from each groupor-set, and thetwo secondary relays will, in turn, be selected andoperated by the energizing of two primary or line relays, while the twoprimary relays will be selected and o 'erated in the manner I havedescribed by t e sendin of two current impulses in succession over t eline wire L, by the de ress on of some one of the 36 transmitting eys atthesending station. In efleet, the individual amen magnets of the seriesof recording or printing magnets are selected and operated by the twosucceeding current impulses, through the intervenin agencies I havedescribed.

which require three or more succeeding im pulses to print a character orperform a corresponding operation and also from other arrangements whichrequire a variable number of impulses for the different characters.Wherever in the following claims I refer to a receiving magnet, or to apair of line relays, or to a pair of succeeding current impulses,corresponding to a letter or character of the transmitted message, itwill be understood that the expression also includes such magnets andpairs of relays or impulses as may correspond to an operation liketheshifting of the typewriter carriage or depression of a shift-keyfor-capitals.

It is to be understood that the principlesof my invention may beextended to sets of relays greater than six or may be otherwise embodieddifierentlyfrom the arrangement shown without departing therefrom.

What I claim as new'gand desire .to secure by Letters Patent is: Y

1. A. telegraph apparatus comprising in combination, two line relays,aseries of receiving magnets each corresponding to a letter or characterof the transmitted message and each selected and operated by the saidrelays, means for-energizing the two relays in succession from a sendingstation by succeeding impulses over a single line wire, and meansconsisting of a separate relay coil and contact for maintaining theeffect of the first impulse until the second impulse has occurred. l

2. A telegraph apparatus comprisin in combination, two line relays, aseries 0 receiving-ma-gnets each correspondin to a letter or characterof the transmitte message and each selected and operated by said relays,means for successively energizing the two line relays by succeedingimpulses over a sin le line wire, and-a series of transmitting eyscorresponding each to one of the several receiving magnets and eachsingle key controlling the transmission of two succeeding currentimpulses.

3. telegraph apparatus comprising in comb1nat1on, a series of receivingmagnets each corresponding to a letter or character of the transmittedmessage and each selected and operated by two succeeding currentimpulses over a single line, each pair of impulses diflering from otherpairs as regards strength or polarity, and means for transmitting suchimpulses in succession from a sending station.

' 4. A telegraph apparatus comprising in combination, a series, ofreceiving magnets each corresponding to a letter or a character of thetransmitted message and each select ed and operated by two succeedingcurrent impulses over a single line, a series of trans mitting contactsat the sending station controlling the strength and polarity of thecurrents to be transmitted, operating magnets for said contacts, andmeans for operating two of said contacts in succession'for each letteror character in the transmitted mes sage.

5. A telegraph apparatus comprising in combination, a seriesof receivingmagnets selected and operated respectively by two succeeding currentimpulses, each of such pairs of impulses corresponding to a letter orpulses, of means for transmitting the desired pairs of impulsescomprising six normally closed circuit breakers in series in the mainline leading from the sending to the receiv ing station, and a normallyopen contact for each'of said circuit breakers connecting with adifferentiated source of electromotive force, with which contact thecircuit-breaker connects at each operation to transmit a differentiatedimpulse overg'the line.

7. In a telegraph system, the combination with a series of receiving*magnets selected and 0 erated respectively by two succeeding anderentiated current'impulses from the sending .station, of means fortransmitting said impulses in pairs differentiated by polarity orstrength from one another, comprising a series of normally-closedcircuit reakers in the main line, a'corresponding number of sources ofelectromotive force differentiated by strength and polarity having theirconnection with the .main line controlled by said circuit-breakers,magnets for magnets and controlling the circuit-breakers in pairs.

' receiving station.

and operated respectively by a set of two succeeding current impulsesdifferentiated from other sets in strength or polarity, of means fortransmitting the differentiated sets comprising sources of electromotiveforce having d' e one terminal permanently connected to ground or to theopposite side of the line, circuit-breakers in series normally closingthe line through the transmitting station and means for simultaneouslyopening a circuit breaker and connecting the free terminal of one ofsaid sources of electromotive force to the line leading from thetransmitting to the 10. In a telegraph system, the combination with aseries of receiving magnets selected and o erated respectively by a setof two succee' ing current-impulses difierentiated from other sets as tostrength or olarity, ofmeans for transmitting the differentiated setscomprising six different sources of electromotive force, sixnormally-closed circuit-breakers in series in the line, and a contactfor each circuit-closer connected to one of said six sources ofelectromotive force for connecting one of said sources to linesimultaneously with the opening of a clrcult closer.

11. In a telegraph system, the combination with a series of receivingmagnets each corresponding to a letter or character of the transmittedmessage and each selected and operated respectively by a set of twosucceeding current impulses differentiated from other sets by strengthor polarity, of a line wire, a series of transmitting contacts,

sources of electromotive force differing in strength and polarity andcontrolled by said contacts, magnets operating said contacts,

and normally-open keys each controlling in succession a set of saidmagnets and pro vided with one-way contacts engaging dur ing one of thetwo directions of movement of the key. 7

12. In a telegraph system, the combina- 'tion with a series of receivingmagnets each corresponding to a letter or character of the transmittedmessage and each controlled respectively by a set of two differentiatedcurrent impulses transmitted in succession over a single line,'a seriesof line relays respondrent values and polarities Withing respectively tothe several impulses, two sets ,of secondary relays acting on thecircuits of the receiving magnets, and a transfer switch for placin thetwo sets of secondary relays alternately in the control of the controlof the line relays, and means for automatically o crating the saidswitch.

14. In a te egraph system, the combination with a series of receivingmagnets con-- trolled respectively by differentiated sets of' succeedingcurrent impulses, of line relays, secondary relays divided into groups,a trans-- fer switch additional to said relays for placing the groupsalternately in the controlof the line relays, and means forautomatically operating said switch after each of the current impulsescomposing one ofthe sets of impulses aforesaid.

15. In a telegraph system, the combination with a series of magnets eachcontrolled respectively by a single differentiated pair of succeedingcurrent impulses, of line relays responding individually to currentsdifferentiated in strength and polarity, circuit-clos ers in series inthe circuit of each of said 'seriesof magnets, and means for operatingsaid jcircuit closers respectively by the several succeeding currentimpulses composing one of the sets of impulses aforesaid.

16. In a telegraph system, the combina tion with a series of receivingmagnets controlled respectively by a differentiated pair of succeedingcurrent impulses on a'single line, of a set of relays operatedalternately by succeeding impulses, a transfer switch and circuitclosers individual to the several receiving relays controlledrespectively by relays from the said'two sets.

17. In a telegraphsystem, the combination with a series of magnetscontrolled respectively by differentiated sets of succeeding currentimpulses on a single line, of a single set of line relays in series, twosets of secondary relays, a transfer switch, additional to said relays,locking devices for the relays operated by one of the current impulsescomposing one of the sets of impulses aforesaid, and circuit closersoperated respectively by secondary relays from the two sets andcontrolling the said receiving magnets;

' 18. In a telegraph system, the combination with a series of magnetscontrolled re spectively by differentiated sets of succeed- .andoperating the circuit closers of sai( ing current impulses, of circuitclosers of said magnets, relays responding to said impulses magnets, atransfer switch additional to said relays, for utilizing said relays insucceeding groups, locking devices and releasing means for said (iGYlCGScontrolled by the operatlon 9 of any one of said series of magnets.

19. In a telegraph system, the combination with a series of magnetscontrolled respectively by differentiated sets of succeeding currentimpulses, of line relays in series, two groups of secondary relays, atransfer switch, a retaining magnet for said switch energized by apreceding, and a shifting magnet therefor energized by a succeedingcurrent impulse. I

20. In a telegraph system, the combination with a series of magnetscontrolled respectively by differentiated pairs of succeeding currentimpulses on a line, of line relays, two sets of secondary relays, atransfer switch, means for shifting said switch on the completion of onecurrent impulse on the line and for returning it on the completion ofthe succeeding current impulse.

21. In a telegraph system, the combination of two sets of magnets eachset containing SIX or more magnets, means for selecting and operatmg oneonly of the first set of magnets by the electrical impulse first received and one only of the second set of mag.

nets by the second electrical impulse received, a series of receivingmagnets controlled each by a single pair of magnets selected andoperated as aforesaid, and means for automatically restoring theapparatus to its original condition after the second impulse.

22. In a telegraph system, the combination of a set of main line relaysresponding to distinctive currents, a line wire over which twosuccessive impulses only are re uired to transmit a character, of twosets 0 secondary relays each equal in number to the said main linerelays, means for automatically disconnecting the first said set ofsecondary relays from the main line relays and connect ing the secondsaid set of secondary relays to the said main line relays after thefirst electrical impulse has terminated, and means for automaticallydisconnecting the second said set of secondary relays from the main linerelays and connecting the first said set of secondary relays to the saidmain line relays after the second said main line impulse has terminated,as and for the purpose described.

23. In a telegraph system the combination of main line relays, two setsof secondary relays, each siX or more in number, an electromagneticswitch having three inde pendent coils, and controlling the operation ofsaid sets of relays, one of said coils receiving current during the timethe contacts of any of said main line relays remain closed for the firstmain line impulse, the second of said coils receiving current onlyduring the time that the contacts of any of said-main line relays remainclosed for the second main line impulse as and for the purposedescribed.

24. In a telegraph system the combination of main line relays, two setsof secondary relays, each six or more in number, a magnetic switchcontrolling the operation of said sets of secondary relays havingindeendent coils, the current in one of said coils eing controlled atsome of the contacts of said main line relays during the first impu seonly, and the current in the second one of said coils being controlledby some of the contacts of said main line relays during the secondsuccessive main line current impulse only, as-and for the urposedescribed.

In witness whereof f have hereunto set my hand before two subscribingwitnesses the third day of January, 1905.

ALBERT C. CREHORE.

Witnesses:

L. T. SHAW, M. A. MODER.

